// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(require('../../lib/codemirror'));
  else if (typeof define == 'function' && define.amd)
    // AMD
    define(['../../lib/codemirror'], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';

  CodeMirror.defineMode('go', function(config) {
    var indentUnit = config.indentUnit;

    var keywords = {
      break: true,
      case: true,
      chan: true,
      const: true,
      continue: true,
      default: true,
      defer: true,
      else: true,
      fallthrough: true,
      for: true,
      func: true,
      go: true,
      goto: true,
      if: true,
      import: true,
      interface: true,
      map: true,
      package: true,
      range: true,
      return: true,
      select: true,
      struct: true,
      switch: true,
      type: true,
      var: true,
      bool: true,
      byte: true,
      complex64: true,
      complex128: true,
      float32: true,
      float64: true,
      int8: true,
      int16: true,
      int32: true,
      int64: true,
      string: true,
      uint8: true,
      uint16: true,
      uint32: true,
      uint64: true,
      int: true,
      uint: true,
      uintptr: true,
      error: true,
      rune: true,
    };

    var atoms = {
      true: true,
      false: true,
      iota: true,
      nil: true,
      append: true,
      cap: true,
      close: true,
      complex: true,
      copy: true,
      delete: true,
      imag: true,
      len: true,
      make: true,
      new: true,
      panic: true,
      print: true,
      println: true,
      real: true,
      recover: true,
    };

    var isOperatorChar = /[+\-*&^%:=<>!|\/]/;

    var curPunc;

    function tokenBase(stream, state) {
      var ch = stream.next();
      if (ch == '"' || ch == "'" || ch == '`') {
        state.tokenize = tokenString(ch);
        return state.tokenize(stream, state);
      }
      if (/[\d\.]/.test(ch)) {
        if (ch == '.') {
          stream.match(/^[0-9]+([eE][\-+]?[0-9]+)?/);
        } else if (ch == '0') {
          stream.match(/^[xX][0-9a-fA-F]+/) || stream.match(/^0[0-7]+/);
        } else {
          stream.match(/^[0-9]*\.?[0-9]*([eE][\-+]?[0-9]+)?/);
        }
        return 'number';
      }
      if (/[\[\]{}\(\),;\:\.]/.test(ch)) {
        curPunc = ch;
        return null;
      }
      if (ch == '/') {
        if (stream.eat('*')) {
          state.tokenize = tokenComment;
          return tokenComment(stream, state);
        }
        if (stream.eat('/')) {
          stream.skipToEnd();
          return 'comment';
        }
      }
      if (isOperatorChar.test(ch)) {
        stream.eatWhile(isOperatorChar);
        return 'operator';
      }
      stream.eatWhile(/[\w\$_\xa1-\uffff]/);
      var cur = stream.current();
      if (keywords.propertyIsEnumerable(cur)) {
        if (cur == 'case' || cur == 'default') curPunc = 'case';
        return 'keyword';
      }
      if (atoms.propertyIsEnumerable(cur)) return 'atom';
      return 'variable';
    }

    function tokenString(quote) {
      return function(stream, state) {
        var escaped = false,
          next,
          end = false;
        while ((next = stream.next()) != null) {
          if (next == quote && !escaped) {
            end = true;
            break;
          }
          escaped = !escaped && quote != '`' && next == '\\';
        }
        if (end || !(escaped || quote == '`')) state.tokenize = tokenBase;
        return 'string';
      };
    }

    function tokenComment(stream, state) {
      var maybeEnd = false,
        ch;
      while ((ch = stream.next())) {
        if (ch == '/' && maybeEnd) {
          state.tokenize = tokenBase;
          break;
        }
        maybeEnd = ch == '*';
      }
      return 'comment';
    }

    function Context(indented, column, type, align, prev) {
      this.indented = indented;
      this.column = column;
      this.type = type;
      this.align = align;
      this.prev = prev;
    }
    function pushContext(state, col, type) {
      return (state.context = new Context(
        state.indented,
        col,
        type,
        null,
        state.context,
      ));
    }
    function popContext(state) {
      if (!state.context.prev) return;
      var t = state.context.type;
      if (t == ')' || t == ']' || t == '}')
        state.indented = state.context.indented;
      return (state.context = state.context.prev);
    }

    // Interface

    return {
      startState: function(basecolumn) {
        return {
          tokenize: null,
          context: new Context((basecolumn || 0) - indentUnit, 0, 'top', false),
          indented: 0,
          startOfLine: true,
        };
      },

      token: function(stream, state) {
        var ctx = state.context;
        if (stream.sol()) {
          if (ctx.align == null) ctx.align = false;
          state.indented = stream.indentation();
          state.startOfLine = true;
          if (ctx.type == 'case') ctx.type = '}';
        }
        if (stream.eatSpace()) return null;
        curPunc = null;
        var style = (state.tokenize || tokenBase)(stream, state);
        if (style == 'comment') return style;
        if (ctx.align == null) ctx.align = true;

        if (curPunc == '{') pushContext(state, stream.column(), '}');
        else if (curPunc == '[') pushContext(state, stream.column(), ']');
        else if (curPunc == '(') pushContext(state, stream.column(), ')');
        else if (curPunc == 'case') ctx.type = 'case';
        else if (curPunc == '}' && ctx.type == '}') popContext(state);
        else if (curPunc == ctx.type) popContext(state);
        state.startOfLine = false;
        return style;
      },

      indent: function(state, textAfter) {
        if (state.tokenize != tokenBase && state.tokenize != null)
          return CodeMirror.Pass;
        var ctx = state.context,
          firstChar = textAfter && textAfter.charAt(0);
        if (ctx.type == 'case' && /^(?:case|default)\b/.test(textAfter)) {
          state.context.type = '}';
          return ctx.indented;
        }
        var closing = firstChar == ctx.type;
        if (ctx.align) return ctx.column + (closing ? 0 : 1);
        else return ctx.indented + (closing ? 0 : indentUnit);
      },

      electricChars: '{}):',
      closeBrackets: '()[]{}\'\'""``',
      fold: 'brace',
      blockCommentStart: '/*',
      blockCommentEnd: '*/',
      lineComment: '//',
    };
  });

  CodeMirror.defineMIME('text/x-go', 'go');
});
